Optometrical instrument



v July 3, 1928.

l. DVORINE OPTOMETRIGAL INSTRUMENT Filed Aug. 16, 1927 Patented July 3, 1928.

UNITED STATI-:s

PATENT OFFICE.

ISRAEL DVOBINE, OF BALTIMORE, MARYLAND.

oP'roMnrnrcAn INSTRUMENT.

Application filed August 16, 1927. Serial No. 213,253.

In obtaining datafor thepreparation of eyeglasses or spectacles having the bifocal lens, considerable dii'liculty has been encountered' in determining the proper location of the intersection or line of contact of the two lens segments. This measurement cannot be treated as constant, not only onaccount of the variation between the corresponding optical dimensions of the diil'erentpatients, but also on account of the variation iniit of the frames and consequently of the position of the lenses relative to the eye, the size of the rims and other variations which can hardly be catalogued. p

The present invention relates to the provision of an instrument wlieieby'tliis data can be obtained immediately in connection with each patient.

In the accompanying drawings I `have illustrated an instrument embodying the features of In invention in the preferred form.

In the crawings: i

` Figure 1 is an elevation of the in upright position.

instrument Figure 2 is a section `at right angles to` Figure 1, of the upper end of the instrument, the same being taken onv the line 2 2 of Figure 1.

Figure 3 is a sectional view taken inthe plane of the axis at right angles to Figure 1, the same being taken on the line 3-3` of Figure 1.

Figure 4 is a general view illstrating the manner of using the instrument in the operation of obtaining data for the construction of bifocal lens spectacles or glasses.

Referring to the drawing by numerals, each of which is used to indicate the same or similar parts in the different figures, the instrument, as shown, consists of a. gauge plate 1 which is preferably of glass or any suitable transparent material and of curved outline, being shown as oval. This gauge plate, as shown, is marked with a suitable scale Q0 and provided with al downwardly projecting supporting sha-ft to which, in the form of the invention shown, it is secured by means of a socket or seatingl member 4 formed on the upper end of the shaft, the plate 1 being iirserted at its lower end in the socketand cementedl or otherwise suitably secured.

The gauge plate 1 and shaft 80 are `mounted in a. suitable casing or support 5 having a tubular handle portion G to enclose the sha-ft() and an enlarged flattened gauge or gauge plate enclosing portion GO at the upper end supported thereon. This plate enclosing portionofithe case is shown as having a slotdike opening 7 at its upper edge 8, which iscurved to conformV to the curve at the lower edge of the eye glass frame or lens. These upper edges 8 are shown as widened to provide a suitable meas uring abutment to engagel the lower side of therim or lens of the glasses or spectacles.

In the form of the invention shown, the supporting shaft 30 is provided with a projecting button or pin 9, most conveniently engaged by the thumb of the operator or Optometrist to move the measuring plate o-r gauge plate up and down, as hereinafter described. To provide a path for the pin 9 as the shaft and plateare moved up and down the tube 6 is slotted in the direction of its axis at 1 0 on one side and is preferably further slotted at 11 for a short distance, the slot extending into the material from the inside ofthe tube 6 and being of leffs depth than the thickness of the material, providing a seat for the spring 12 which bears against the shaft 30, creatine suiicient friction to hold the parts in adjusted or measuring position.

` In the operation of the invention, i. e., in the use of the instrument to obtain the desired data, the patient is first fitte-d with a suitable eye glass or spectacle frame 14, as shown in Figure 4. The Optometrist, standing in front of the patient, then places the abutment 8 in contact with the lower side of the spectacle rim 16, the operation being performed on each rim successively, and holding the handle 6 below the rim in a position which is substantially vertical, the thumb being engaged with the pin or button 9, as shown in the view Figure 4, he moves the measuring plate 1 to a position in which the upper edge of the same at 15 is in the posi tion which, in his judgment should be occupied by the line of intersection of the two segments of the bifocal lens. This measure ment between the upper edge of the gauge plate 15 and the edge or abutment 8 is indicated by the scale Q and is then suitably recorded and used in the preparation of the spectacles or eye glasses.

In case it is desired to obtain this data. in eonnectionwith the preparation of a one piece bifocal lens glasses without rims, a

trame with any suitable lenses, plain or otherwise, of the dimension which it is desired to give the lens in the linished product may be fitted and the measurement obtained as already described in connection with the glasses having rims. The original lenses, being the exact shape ot' the finished bifocals, are then removed and the finished bifocals substituted.

.lt will be noted that while the gradnations 2O on the measuring plate l begin at l0, the Lgraduation mark l is spaced downwardly trom the upper edge l5 of the measuring plate a. distance oit ten units. The exact manner ot graduation ot the plate is, however, immaterial.

I have lthus described specil'ically and in detail an instrument embodying my invention in the preferred `torni in order that the nature and operation eli the same may be clearly understood, liewever, the specific terms herein are nsid descriptively rather than in a limiting` sense, the scope of the invention being delined in the claims.

that I claim as new and desire to secure by Letters Patent is:

l. The combination in an instrument for Y determining by measurement taken from the patient the position o'l' the line et intersection oit' the segments o't a bitocal lens or spectacles which consists of a transparent oval measuring plate, a casing lor the same slotted to admit the measuring plate and having a measuring almtment adapted to -contact the edge el" a spectacle rim, the casof intersection of the segments of the bifocal lens to the rim.

2. The combination in an instrument for determining by measurement taken from the patient the position ofthe line of intersection of the segments ot a-bifocal lens or spectacle which consists of a support, a measuring abutment, al measuring plate mounted to slide transversely to the abutment and means for engagement by the hand whereby the plate may be moved up and down in lront of the eye as the abutment is held in contact with the rim of an eye glass worn by the patient.

3. The combination in an instrument for determining by measurement taken `from the patient the position ot' the line of intersection otf the segments ot' a bifocal lens er spectacle which consists of a support having a handle, a measuring abutment, a measuring plate mounted to slide transversely to the abutment and means for engagement by the hand whereby the plate may be moved up and down in t'ront of the eye as the abutment is held in contact with the rim of an eye glass worn by the patient.

1. The combination in an instrument for obtainingl by measurement taken from the patient the proper position for the line of the intersection of the segments ot a bitocal lens which consists of a support having an abutment, a measuring plate mounted to slide on the support transversely to the abut- 4ment, a handle for the support and means connected to the measuring plate to be engaged by the thumb ot the hand grasping the handle to move the measuring plate relatively to the abutment.

Signed by me at Baltimore, Maryland, this th day of August, 1927.

ISRAEL DVORINE. 

